An ecologically correct electroanalytical method to determine the herbicide Picloram in Amazon waters using a miniaturized boron-doped diamond electrode and a 3D compact electrochemical cell

In situ voltammetric analysis of 2,4-dichlorophenoxyacetic acid in environmental water using a boron doped diamond electrode and an adapted unmanned air vehicle sampling platform

“…30,31 Based on this electrochemical data from CV, the rate of analyte transfer to the BDDE surface depends on the concentration gradient, with the I p linearly proportional to the 2,4-D concentration; thus, the analytical curves method can be used to quantify the 2,4-D. Moreover, the displacement of the oxidation potentials to more positive values with an increase of the scan rate confirmed the irreversibility of the oxidation process, 21 Fig. 3.…”

“…This procedure performs an electrochemical cleaning of the electrode surface. 16–21 After the treatment, cyclic voltammetry using 0.1 mmol L −1 K 3 [Fe(CN) 6 ] in 0.1 mol L −1 KCl was carried out in order to verify the electrochemical behavior of the pretreated BDDE, by checking the electrochemical reversibility of the Fe 2+ /Fe 3+ redox pair. In sequence, before using the pulse voltammetric method for 2,4-D detection, 20 to 25 cyclic voltammograms were performed at 50 mV s −1 in a potential range from 0 to 1.8 V vs. Ag/AgCl (3.0 mol L −1 KCl) to stabilize the BDDE surface.…”

“…For GC-MS method, toluene was used for this dilution. This procedure is common in the literature, similarly employed by de Figueiredo-Filho et al 29 and dos Santos et al 21…”

“…The study of possible interferent compounds were focused on some cations and anions compounds widely studied for analysis of environmental water, such as K + , Cu 2+ , Cl − , and NO 3 − , which are common in freshwater where a concentration of 10.48 μmol L −1 2,4-D in a 1 : 100 ratio (analyte : interfering) is found. 21,29 The results obtained were expressed in terms of relative error based on variation of the I p supplied by the analyte concentration due to the presence of the interferent species. The recovery was performed at levels of 0.5 μmol L −1 and 0.9 μmol L −1 at diluted spiked samples with a concentration of 0.5 μmol L −1 with the electrochemical measures performed in triplicate ( n = 3).…”

“…The recovery was performed at levels of 0.5 μmol L −1 and 0.9 μmol L −1 at diluted spiked samples with a concentration of 0.5 μmol L −1 with the electrochemical measures performed in triplicate ( n = 3). 21…”